1. Field of the Invention
The present invention relates to the use, in transparent aqueous cosmetic compositions for rinsing, of at least one amphoteric surfactant as an agent for precipitating hydrosoluble or hydrodispersible cationic polymers derived from polysaccharides (in particular cationic celluloses and hydroxyalkylated cationic guars) included in said compositions, on dilution during application of said compositions to the hair and/or the skin; it also relates to aqueous cosmetic compositions for the hair and/or the skin comprising, in addition to said amphoteric surfactant, at least one anionic surfactant, at least one surfactant selected from betaines and at least one hydrosoluble cationic polymer derived from a polysaccharide.
2. Background
Human hair or skin becomes dirty on contact with atmospheric pollution and to a greater extent with natural secretions such as sebum. This phenomenon necessitates cleaning the skin and hair frequently using cosmetic compositions. While their detergent properties are usually largely satisfactory, frequent and repeated washing often leaves the hair in a condition which requires a complementary treatment. Different solutions have been proposed to overcome this problem, from using conditioning agents included in the cosmetic formulation to developing specific products used in a post treatment.
For cost and effectiveness reasons, it is desirable to maximise the deposit of conditioning agents on the hair and/or skin. A general approach consists of using associative interactions between an anionic surfactant and a cationic polymer, which interactions lead to precipitation of a surfactant/polymer complex on the desired surface. Examples which can be cited are formulations based on the sodium lauryl ether sulphate/cocamidopropylbetaine and guar hydroxypropyl trimonium chloride system such as Jaguar C13S sold by Rhone-Poulenc. That system precipitates on dilution by phase separation, leading to an increased deposit of the polymer on the surface of the hair and/or skin. However, that system cannot produce formulations with the desired transparency.
One solution for improving transparency consists of using hydroxypropyl guar hydroxypropyl trimonium chloride such as JAGUAR C162 sold by Rhone-Poulenc, but the system formed by association with the surfactants cited above do not precipitate on dilution.
The Applicant has unexpectedly discovered that addition of a small quantity of an amphoteric type surfactant to an aqueous transparent medium containing an anionic surfactant, a surfactant of the betaine type and a hydrosoluble or hydrodispersible cationic polymer derived from a polysaccharide which does not precipitate out on dilution by phase separation (cationic celluloses and hydroxyalkylated cationic guars in particular) can, on dilution, precipitate said cationic polymer by a phase separation phenomenon.
For cosmetic applications, this precipitation causes a substantial increase in the deposit of the cationic polymer derived from a polysaccharide on the hair and/or skin, when said aqueous medium is diluted by contact with the damp and/or wet hair and/or skin.
This system can also be used to simultaneously increase the deposit of non hydrosoluble organic cosmetic agents which can be present in the form of dispersions of particles.